Template:Are You Sure/February 10

• ... that astronomer, astrologer, cartographer, and mathematician Giovanni Antonio Magini devised his own geocentric planetary theory, and that the Maginian System consisted of eleven rotating spheres, which he described in his Novæ cœlestium orbium theoricæ congruentes cum observationibus N. Copernici (Venice, 1589)?

• ... that Magini also described the use of quadrants in surveying and astronomy, devised extremely accurate trigonometric tables, worked on the geometry of the sphere and applications of trigonometry (for which he invented calculating devices), and published on the theory of concave spherical mirrors?